Computerized GoTo Telescope

Overview

A computerized GoTo telescope is a Newtonian reflector mounted on a motorised equatorial head that can find and track celestial objects automatically. The user aligns the instrument on a few reference stars, then selects a target from the hand controller's database; geared stepper motors slew both axes to point the tube and then drive the right-ascension axis at sidereal rate to keep the object centred against Earth's rotation. It removes the hardest part of amateur astronomy, locating faint objects by hand, while a fast f/5 mirror delivers bright, wide views.

How it works

The Optical Tube Assembly is a Newtonian: a parabolic primary mirror at the base, held in the collimatable Primary Mirror Cell, reflects light back up the tube to a flat Secondary Mirror Assembly mirror angled at 45°, which diverts the focused cone out the side into the Rack-and-Pinion Focuser. A rack-and-pinion focuser racks the drawtube and eyepiece to the focal plane, and an attached finderscope aids initial pointing.

Image magnification comes from the eyepieces. A four-element Plossl Eyepiece Plössl in a 1.25-inch barrel, supported by a Barlow and star diagonal in the Barlow & Diagonal Set set, gives a range of powers from one mirror. The whole tube rides on the Equatorial GoTo Mount Head, an equatorial head whose RA and DEC axes are each a worm-and-wheel drive turned by a geared GoTo Stepper Motor stepper with an optical encoder for position feedback; counterweights balance the tube about the polar axis.

The Mount Control Board commands the steppers and reads a GPS module for automatic time and location, while the Hand Controller holds the object database and slew keypad. With one polar-aligned setup, the mount can sweep across the sky to any catalog object and hold it steady for visual observation or long-exposure imaging.